Process for the production of noninflammable celluloid



ARTHUR nrcnnlvoniilv, or BERLIN, GERMANY, ASSIGNOR, BYMnsNEassrenmnn'rs, 'ronmnnromv cnnnonn COMPANY 11510.), or new YORK, N, a, Acoaroanrron on NEW YORK.

PROCESS FOR THE PRODUCTION OF 1\l'01 '.l'I1\[1*LAMIMILAIBLE 'CEIlLULOIIYI).

Specification of Letters Patent, Patented June 20, 1922,

No Drawing. Application filed November 23, 1910, Serial No. 593,773.Renewed August 31, 1921.

Serial No. 4973401,.

(GRANTED unnna rnn rnovrsions or THE ACT or'mnncn a, 1921, 41 sun I...181 8 have invented certain new and useful Improvements in a Process forthe Production of Noninflammable Celluloid (for which I have 'filedapplication in Germany Nov. 29, 1909) and I dohereby declare that thefollowing is a full, clear, and exact description thereof. a

It has been pointed out for some time that the non-inflammable acetylcellulose ought to be suitable on account of its similarity tonitro-cellulose for producing celluloid-like but non-inflammable masses.However, the experiments made in this direction have not yet led to adefinite result, although a series of camphor substitutes have becomeknown, which in connection with acetyl cellulose appear suitable to givecelluloid-like masses.

The reason for the failure of these experiments lies in the fact thatwhen melting acetyl cellulose with camphor substitutes with orwithoutthe employment of pressure, and in the cold or in the hot state,such large amounts of camphor substitutes had to be taken for dissolvingthe acetyl cellulose, that the mass thus obtained was plastic but nothard and resilient like celluloid. With the small amounts of camphorsubstitutes which have to be employed for obtaining a hard celluloid,acetyl cellulose could not be treated without employing a solvent, suchas chloroform, acetone, ethyl acetate, glacial acetic acid,nitro-benzeneiand the i like. If one added ,large amountsof thesesolvents then perfect solutions orpulpy pastes were obtained, from whichthe solvent evaporated onlyslowly and so imperfectly that the massremained soft and could not be used for-jaiglong time. If, however, onlysmall amounts of solvents -were employed, they were absorbed by partsonly of the acetyl cellulose, whereasother parts remained perfectly dry,so that only nonhomogeneous sticky mixtures resulted.

Now I have found that by employing such small amounts of camphorsubstitutes as allow of obtaining a hard final product, acetyl Iphorsubstitutes with the acetyl cellulose,

cellulose can be brought into a swollen or. gelatinous state, from whichhard, perfectly celluloid-like masses can be obtained if a uniformdistribution of the camphor substitutes with the powderedacetyl-cellulose (which in weight and volume is considerably greaterthan that of the camphor substitutes); In order to effect this uniformdistribution, the camphor substitutes 'are dissolved in a suitableliquid solvent in such quantity that the acetyl cellulose is uniormlywetted. by this solution upon being thoroughly mechanically kneadedtherewith. This kneading or mechanical working is most efiicacious whencarried on at a high temperature.

As solvents, volatile liquids can be used which may or may not besolvents of acetyl cellulose. In'the first case, however, it ispreferable to use these solvents of acetyl 7 cellulose not pure but inmixture with other liquids which do not dissolve acetyl cellu-' lose, inorder toprevent the formationof viscous acetate solutions.

vents of acetyl cellulose are used, they are intended only to enabletheuniform distri bution of the admixtures by continued workmg and aswelling up or loosening of the acetate grains, and not to completelydissolve the acetate cellulose, so that only a swelling up of the?latter resultsijj y,

The essenti' l advantage of this process consists in the fact, that onecan work with volatile, solventor the volatile mixture results, but onlysuch a swelling as is necessary for effecting a combination of the cam-As camphor substitutes such bodies are regarded, which have a highboiling point, and which, in a liquid or molten condition, have asolvent action on the kind of acetyl cellulose in question, moreparticularlv amides 9 and their derivatives, esters of acids.

' Example I; g

100 parts of acetyl cellulose solublein glacial' acetic acid aresubmersed in amixture 100 In every case, however,where volatile sol- 75of 75 parts of alcohol and 50 parts of dichlorhydrine and are mixedtogether until the liquid is uniformly absorbed by the acetyl cellulosepowder. The mass is then heated under constant mechanical kneading untilit is converted into a gelatinous state, and is then rolled out in theform of discs and carried through heated rollers until the alcohol'isevaporated.

Example. I.

Eazample III.

100 parts of acetyl cellulose soluble in acetone are wetted with amixture of 75 parts of alcohol and 75 parts of acetone and 40 parts ofmanol are added. The mass is kneaded at a temperature of 40 and aswelling results. Then the temperature is in creased to 65 C. and aftersome time perfectly gelatinous masses are obtained, which are worked inthe usual manner.

Ewwmple I V. v 100 parts of acetyl cellulose soluble in ethyl acetateare moistened with 100 parts .to this means a substance which is a nonofmethyl alcohol in which 30 parts of naphthyl-acetate are dissolved.After the mass is thoroughly mixed 100 parts of tetrachlorethane aregradually added in small quantities under constant kneading.-

Upon continued kneading after a short time a perfect swelling up, andthen a uniform solution results, although the acetyl cellulose solublein ethyl acetateis neither soluble in methyl alcohol nor in tetrachlor--ethane alone.

It will of course be understood that where a non-solvent for acetylcellulose is referred solvent or practically so for the particularacetyl cellulose employed and that in the practical carrying out of thehereindescribed process the selectionof a non-solvent should be madecarefully and with particular reference to the make .or brand of acetylcell-u lose because this material may vary consid erably in regard toits solubility.

In the clalms appended hereto no mention is made as to whether theprocess defined by each claim is to be carried out in the-cold or withthe application of heat, it being understood that, wherever the languageof any presence" of two witnesses,

claim-permits ofit, the claim is to be construed broadly to cover eithermethod.

Also, where two or more liquids are specified in a claim, it is'to beunderstood that those liquids may be used in any manner or in anyrelative order that is practicable, even where such liquids are-referredto as constituting a mixture. The Word mixture is not necessarily to betaken as implying that the various individualliquids in questlon arebrought together pkior to being added to the acetyl'cellulose, as suchliquids forming the so-calledmixture would in some cases be introducedone after the other and moreover the order in which they are introducedneed not be the order in ,which they are named. I What I claim as newand desire to secure by Letters Patent ism 1. A process for thegpi'dduction of hardcelluloid material from acetyl cellulose consistingin mixing acetyl cellulose together with a camphor substitute and avolatile solvent for the acetyl cellulose, said volatile solvent beingused in quantities insuflicient to effect complete solution of theacetyl cellulose and in mechanically working or kneading said mixtureuntil a composition results which on evaporation of the volatile solventsolidifies to a hard celluloid like mass.

2. A process for the production of hard celluloid material from acetylcellulose consisting in mixing acetyl cellulose together with a camphorsubstitute and a volatile solvent both for the camphor substitute andthe acetyl cellulose, said volatile solvent being'used in quantitiesinsuflicient to effect complete solution of the acetyl cellulose and inmechanically workingor kneading said mixture until a composition resultswhich on evaporation of the volatile solvent solldifies to a hardcelluloid like mass.

3.-A rocess for the production of hard celluloid material from acetylcellulose consisting in mixing acetyl cellulose together with a camphorsubstitute and a volatile liquid having a solvent action on said acetylcellulose at the temperature employed, said volatile liquid being usedin quantities insufficient to effect complete solution of the. acetylcellulose and in mechanically working or kneading said'mixture until acomposition results which on evaporation of the volatile liquidsolidifies to a hard celluloidlike mass.

In testimony that I claim the foregoing as my invention I afiix mysignature in the November, A. 111910. I

' ARTHUR -EICHENGRllN. FWitnesses: 4 r HENRY HASPER,

WOLDEMAR

